Emission Control Components Glossary

Emission control components reduce harmful emissions by managing exhaust gases, fuel vapors, and other pollutants, ensuring compliance with environmental standards and improving air quality. Here’s a comprehensive guide to understanding these essential components.

1. Catalytic Converter

The catalytic converter reduces toxic gases in the exhaust by converting them into less harmful emissions. Using catalysts like platinum and palladium, it converts carbon monoxide, hydrocarbons, and nitrogen oxides into carbon dioxide, water vapor, and nitrogen.

2. Oxygen Sensor

Located in the exhaust system, the oxygen sensor measures oxygen levels in the exhaust gases. It helps the engine control module adjust the air-fuel mixture for optimal combustion, improving fuel efficiency and reducing emissions.

3. Exhaust Gas Recirculation (EGR) Valve

The EGR valve recirculates a portion of the exhaust gas back into the engine’s intake to lower combustion temperatures, reducing nitrogen oxide (NOx) emissions.

4. EGR Cooler

The EGR cooler reduces the temperature of the exhaust gases before they re-enter the engine, further reducing NOx emissions and helping the EGR system function efficiently.

5. Evaporative Emission (EVAP) Canister

The EVAP canister stores fuel vapors from the fuel tank, preventing them from escaping into the atmosphere. The vapors are then directed back into the engine for combustion.

6. Diesel Particulate Filter (DPF)

The DPF captures soot and ash from diesel exhaust, filtering out particulate matter to reduce emissions. It regenerates periodically by burning off the accumulated particles.

7. EGR Tube

The EGR tube connects the EGR valve to the engine’s intake, carrying recirculated exhaust gases back into the engine for re-combustion.

8. Exhaust Back Pressure Sensor

This sensor monitors exhaust system pressure, allowing the engine control module to adjust the EGR valve to optimize exhaust flow and emissions.

9. EGR Valve Position Sensor

The EGR valve position sensor monitors the position of the EGR valve, ensuring precise control of the exhaust gases re-entering the engine.

10. Air Injection Pump

The air injection pump introduces fresh air into the exhaust stream to help reduce emissions, especially during cold starts. This assists in burning off excess fuel in the exhaust.

11. EGR Gasket

The EGR gasket seals the connection between the EGR valve and the intake manifold or EGR cooler, preventing exhaust gas leaks.

12. EVAP Purge Solenoid

The EVAP purge solenoid controls the flow of fuel vapors from the EVAP canister to the intake manifold, allowing them to be burned in the engine.

13. Exhaust Pressure Regulator

The exhaust pressure regulator controls exhaust pressure to ensure optimal performance and emissions control, commonly found in turbocharged diesel engines.

14. SCR Catalyst (Selective Catalytic Reduction)

The SCR catalyst reduces NOx emissions by injecting a reductant (like DEF) into the exhaust stream, transforming harmful gases into nitrogen and water.

15. Particulate Filter Sensor

The particulate filter sensor monitors the amount of particulate matter in the DPF, signaling when regeneration or cleaning is needed.

16. NOx Sensor

The NOx sensor measures nitrogen oxide levels in the exhaust, helping optimize the SCR system for emission reduction in diesel engines.

17. EGR Valve Solenoid

The EGR valve solenoid controls the EGR valve’s opening and closing, allowing precise management of exhaust gases re-entering the engine.

18. Evaporative Emission Hose

The EVAP hose connects components in the EVAP system, such as the fuel tank, canister, and purge valve, directing fuel vapors for storage and re-combustion.

19. O2 Sensor Connector

The O2 sensor connector links the oxygen sensor to the engine control module, transmitting data on exhaust oxygen levels for air-fuel mixture adjustments.

20. EVAP Purge Valve

The EVAP purge valve releases fuel vapors from the EVAP canister into the intake manifold, allowing them to be combusted in the engine.

21. EGR Cooler Gasket

The EGR cooler gasket seals the EGR cooler connections, preventing leaks of exhaust gases and coolant.

22. Exhaust Flange

The exhaust flange joins sections of the exhaust system, providing a secure, sealed connection for components like pipes, mufflers, and catalytic converters.

23. EGR Control Valve

The EGR control valve regulates the flow of recirculated exhaust gases, enabling precise control over emissions.

24. Crankcase Breather Filter

The crankcase breather filter captures oil vapors from the crankcase, preventing them from escaping into the environment and recycling them back into the engine.

25. Air Injection Hose

The air injection hose carries fresh air from the air injection pump to the exhaust system, helping to reduce emissions by supporting combustion of unburned fuel.

26. EGR Valve Assembly

The EGR valve assembly includes the EGR valve and related components that work together to recirculate exhaust gases and reduce NOx emissions.

27. Air Injection Check Valve

The air injection check valve prevents exhaust gases from flowing back into the air injection system, ensuring only fresh air enters the exhaust.

28. Evaporative Canister Vent Valve

The vent valve allows the EVAP system to release trapped fuel vapors under controlled conditions, preventing them from escaping into the atmosphere.

29. Emission Control Module

The emission control module manages various emission-related components, ensuring the vehicle meets emissions standards.

30. Catalyst Temperature Sensor

This sensor monitors the temperature of the catalytic converter, ensuring it remains at optimal operating temperature for effective emission control.

31. PCV (Positive Crankcase Ventilation) Valve

The PCV valve vents unburned gases from the crankcase back into the intake manifold, reducing harmful emissions and improving fuel efficiency.

32. EVAP Canister Vent Solenoid

The EVAP canister vent solenoid opens and closes to control the release of fuel vapors from the EVAP system, ensuring they are re-circulated for combustion.

33. Secondary Air Injection Valve

The secondary air injection valve controls the flow of secondary air into the exhaust, improving emissions control during cold starts.

34. Diesel Oxidation Catalyst

The diesel oxidation catalyst reduces emissions by oxidizing carbon monoxide and hydrocarbons into carbon dioxide and water.

35. Exhaust Gas Temperature Sensor

The exhaust gas temperature sensor monitors exhaust temperature, providing data to prevent overheating and ensure emissions control systems function efficiently.

36. Air Pump Relay

The air pump relay controls the air injection pump’s operation, providing fresh air to the exhaust system during emissions control processes.

37. EVAP Vent Filter

The EVAP vent filter prevents debris from entering the EVAP system, maintaining its effectiveness in controlling emissions.

38. Exhaust Gasket

The exhaust gasket seals connections in the exhaust system, preventing leaks and ensuring proper emissions control.

39. EGR Valve Pipe

The EGR valve pipe directs exhaust gases from the EGR valve into the intake manifold, enabling recirculation and reducing NOx emissions.

40. Fuel Vapor Canister

The fuel vapor canister, part of the EVAP system, stores fuel vapors to prevent them from escaping into the atmosphere, later releasing them for combustion.

41. Secondary Air Injection Pump

The secondary air injection pump supplies fresh air to the exhaust system, promoting the oxidation of unburned hydrocarbons for emissions reduction.

42. Exhaust Flow Valve

The exhaust flow valve controls the direction of exhaust gases, aiding emissions control and performance in some vehicles.

43. PCV Breather Hose

The PCV breather hose channels gases from the crankcase back into the engine intake for re-combustion, reducing emissions.

44. DPF Pressure Sensor

The DPF pressure sensor monitors the soot levels in the diesel particulate filter, prompting regeneration when levels are high.

45. Emission Vacuum Control Valve

This valve regulates vacuum flow to various emission control components, ensuring optimal operation of emissions-reducing systems.

46. Exhaust Resonator

The exhaust resonator reduces exhaust noise and can enhance flow efficiency, indirectly aiding emissions control by supporting optimal engine function.

47. Emission Control Vacuum Hose

These hoses connect various emission components, directing vacuum pressure where needed to operate emission control devices effectively.

48. Carbon Canister Filter

The carbon canister filter captures fuel vapors, preventing them from escaping into the atmosphere and reducing hydrocarbon emissions.

49. Air Injection Control Valve

This valve regulates the amount of fresh air entering the exhaust system, ensuring efficient emissions control.

50. Catalytic Converter Clamp

The catalytic converter clamp secures the catalytic converter to the exhaust pipe, preventing exhaust leaks and ensuring emissions control.